1. Field of the Invention
The present invention relates to a television tuner that receives a television signal using a smart antenna.
2. Description of the Related Art
In television broadcast, transmitting points of broadcast stations may be different from one another. In this case, if television broadcast services provided by the broadcast stations are received at a certain receiving point, a television receiver must be brought to a state in which the receiver can receive a television signal on a desired reception channel. Moreover, the directivity of an antenna must be adjusted so that the antenna will be directional to the transmitting point at which a television signal is transmitted on the reception channel.
In the past, a television receiver including a smart antenna whose directivity can be statically varied with an electric signal has been known (refer to, for example, Japanese Unexamined Patent Publication No. 22-298226). In the television receiver, when change of reception channels is instructed by manipulating a remote control or the like, the receiving direction of the smart antenna or a direction in which the smart antenna receives a television signal is automatically varied in order to scan television radio waves sampled in all directions so as to thus detect a direction in which television radio waves are received under satisfactory conditions.
However, when the television receiver described in Patent Document 1 is instructed to change reception channels by manipulating a remote control or the like, television signals sampled in all the directions of the smart antenna are scanned in order to detect a direction in which a satisfactory television signal is received. When image quality is degraded during reception of a television broadcast service on the same channel, if television signals sampled in all the directions are rescanned to detect a receiving direction in which a satisfactory television signal is received, the reception channel must be temporarily switched to any other channel. Thereafter, the channel must be returned to the original reception channel. This is time-consuming.